Not applicable
The present invention relates to a gas rotary screw compressor, in particular, for low-power air conditioning or refrigeration systems.
Rotary compressors normally comprise a casing housing a male rotor meshing with a female rotor. Such compressors, however, are used for handling large quantities of gas, in particular, cooling gas such as Freon.
For low-power (3-7 hp) applications, reciprocating compressors have always been used on account of the problems encountered in adapting rotary compressors to low-power systems.
One of the main problems encountered when designing a rotary compressor for low-power, e.g. 3-7 hp, air conditioning or refrigeration systems is achieving optimum fill of the compressor to ensure an acceptable degree of efficiency. That is to say, difficulty is encountered in initiating the intake stage of compressors operating at fairly low male rotor rotation speeds; and, if severe load losses occur at the start of the intake stagexe2x80x94due to poor design of the conduits supplying gas to the rotors of the compressorxe2x80x94the gas expands. Both the above result in impairment of the fill factor of the compressor, which becomes more noticeable as the mass of gas being handled gets smaller. Moreover, if the gas supply conduits, the male and female rotors, and the gas/lubricant mixture discharge conduits are not designed properly, there is a danger the rotors may even operate like a fan and feed the gas, which should be aspirated, back to the supply conduits.
It is an object of the present invention to provide a gas rotary screw compressor designed to eliminate the aforementioned drawbacks.
According to the present invention, there is provided a gas rotary screw compressor, in particular, for low-power air conditioning or refrigeration systems, as described and claimed in claim 1.
The gas compressed by the screw compressor could be any kind of gas, in particular, Freon or air.